1. Operating System Commands

2. Commands External / internal command In MS-DOS there are two types of commands. An Internal command, which is a command embedded into the command.com file, and an external command, which is not embedded into command.com and therefore requires a separate file to be used. For example, if your computer does not have fdisk.exe and you try using the fdisk command, you would receive an error "Bad command or file name." Fdisk is an external command that will only work if fdisk.exe, or in some cases, fdisk.com, is present. However, as long as MS-DOS is running on your computer internal commands such as the cd command will always be available and does not require any other files to run.

3. Commands Internal command A command that is stored in the system memory and loaded from the command.com. Below are examples of internal commands in MS-DOS currently listed Cls Time Type Ver Chdir Copy Date Del Dir ….

4. Commands External command A MS-DOS command that is not included in command.com. External commands are commonly external either because they require large requirements or are not commonly used commands. Below are examples of MS-DOS external commands Fdisk Find Format Xcopy Ping …..

5. Commands